Cylinder for internal combustion engines



April 28, 1959 K. LANGMAIER 2,383,977

CYLINDER FOR INTERNAL COMBUSTION ENGINES Filed May 20, 1955 v 5 L F162 i l 2 ll 3 IN VE N 7'02 7, [air /insinir/e'w/ 179-1.

United t CYLINDER FOR INTERNAL COMBUSTION ENGINES Karl Langmaier, Ulm (Danube), Germany, assignor to Kliickner-Humboldt-Deutz Aktieugesellschaft, Koln- Deutz, Germany The present invention relates to internal combustion engines and, more particularly, to directly air-cooled cylinders for internal combustion engines. The invention is especially directed to the connection of a separately manufactured cylinder head to a cylinder of the above mentioned type.

In order, with such directly air-cooled cylinders the flow of cooling air over the cylinder, to prevent head from being impeded by the head of connecting bolts and installations pertaining thereto, and in order to avoid interrupting the cooling fins at such places, it has been suggested to cause the connecting bolts to engage the cylinder head from below. To this end, the cylinder head is provided with an enforced marginal section having threaded bores therein which are engaged by correspondingly threaded portions of the connecting bolts, whereas the heads of such bolts engage a flange provided on said cylinder below said cylinder head. Such an arrangement has the drawback that the said flange on the cylinder considerably affects the heat conduction away from the cylinder in as much as such flange is arranged within the normal area of the cooling fins of said cylinder.

It is, therefore, an object of the invention to provide a cylinder-cylinder head arrangement, which will overcome the above mentioned drawback.

It is another object of this invention to provide a directly cooled cylinder-cylinder head arrangement which for all practical purposes forms an entirety and can be removed and installed as such whenever it should be desirable to do so.

These and other objects and advantages of the invention will appear more clearly from the following specification in connection with the accompanying drawing, in which:

Fig. 1 is a longitudinal section through a cylindercylinder head arrangement according to the invention showing the connection thereof with the engine casing.

Fig 2 is a side view of the arrangement shown in Fig. 1, the cylinder head being removed.

Fig. 3 is a top view of the cylinder shown in Fig. l.

The invention consists primarily in that the bolts engaging the cylinder head from below and connecting the same to the cylinder engage the same flange which serves for connecting the cylinder to the engine casing. At that area where the said flange is located, the quantity of heat to be conducted away from the cylinder is so small that the said flange does not affect the cooling process. This arrangement has the further advantage of allowing the employment of bolts of relatively high tensile elasticity, which bolts are highly desirable in view of the greatly varying loads and temperatures. While this advantage is also present with a known structure in which the cylinder head connecting bolts serve at the same time as connecting bolts for the cylinder and to this end engage the engine casing, with this known structure, the connecting bolts are introduced into the engine casing from the cylinder head side. Consequently, when this known arrangement is used with an air cooled engine, the heads tes Patent ice of said bolts greatly affect the air cooling of the engine, which drawback is avoided with the arrangement according to the present invention.

The connection of the cylinder head in conformity with the present invention has the further advantage that the cylinder head connecting bolts can be tightened uniformly at the manufacturing plant to a desired extent and that later on, when a removal of the cylinder should be desirable, it is not necessary to disconnect the cylinder from the cyclinder head. Instead, the cylinder and cylinder head form an entirety with each other and can be removed and re-installed as such.

Referring now to the drawing in detail, the structure shown therein comprises a cylinder 1 for a four stroke cycle internal combustion engine. The lower end of cylinder 1 is provided with an annular flange 2 for connecting the cylinder 1 to the engine casing 3. The upper end of the cylinder 1 is provided with a neck 1a for cen tering the cylinder head 6 on the cylinder while a gasket 1b is interposed in customary manner between the cylinder head and the cylinder. The cylinder head 6 also carries in customary manner the valves 4 and a spark plug 5. The cylinder head 6 is connected to the cylinder 1 by means of connecting bolts 7 having a threaded section 8 which latter is screwed into a correspondingly threaded bore provided in the enforced marginal portion or annular section 9 of the cylinder head 6. The heads 10 of the connecting bolts 7 engage the connecting flange 2 of the cylinder 1. As will be seen from the drawing, the lower surface of flange 2 is provided with recesses 11 wherever the flange 2 is to be engaged by the heads 10 of bolts 7. Screws 12 for connecting the cylinder 1 to the engine casing 3 are respectively arranged adjacent the heads 10 of bolts 7. The short distances between each two adjacent heads 10 and screw 12 bring about low bending stresses in flange 2.

When the cylinder 1 for some reason has to be removed from the engine casing 3, it is merely necessary to unscrew the screws 12, whereas the tension screws or bolts 7 may remain in their tightened condition.

It is, of course, understood that the present invention is, by no means, limited to the particular construction shown in the drawing but also comprises any modification within the scope of the appended claims.

What I claim is:

1. In combination: a cylinder head provided with cooling fins, and with threaded bores arranged within the circumferential range of said cooling fins a cylinder provided with cooling fins and having one end connected to said cylinder head, flange means integral with said cylinder and arranged in spaced relationship to said cylinder head, said flange means having a first surface facing said cylinder head and having an opposite surface facing away from said cylinder head, an engine casing adjacent said flange means, connecting means interconnecting said flange means and said engine casing, and bolt means arranged near said connecting means within the circumferential range of extension of the cooling fins of said cylinder and connecting said cylinder head to said flange means, said bolt means having one end only provided with a head engaging that surface of said flange means which faces away from said cylinder head, the other end of said bolt means being provided with a thread threadedly engaging said threaded bores of said cylinder head.

2. In combination with an air cooled cylinder for internal combustion engines: a cylinder head provided with cooling fins and mounted on said cylinder, said cylinder head being provided with threaded bores closed at the end remote from said cylinder, flange means integral with said cylinder and arranged in spaced relationship to said cylinder head, said flange means having a first surface facing said cylinder head and having an opposite surface facing away from said cylinder head, an engine casing adjacent said opposite surface of said flange means, said opposite surface being provided with recesses, a plurality of first connecting bolts having one end thereof provided with a theraded section engaging said threaded bores and having the other end thereof provided With a head engaging said opposite surface of said flange means, and second connecting bolts extending through said flange means and interconnecting said engine casing and said flange means, the arrangement being such that each first bolt is adjacent a second bolt.

3. An arrangement according to claim 2, in which the 41 axes of said first and second bolts are located substantially along one and the same circle References Cited in the file of this patent UNITED STATES PATENTS 1,857,077 Adamson May 3, 1932 1,867,795 Angle July 19, 1932 2,563,348 Lyman Aug. 7, 1951 2,638,081 Spannhake May 12, 1953 2,670,726 Spannhake Mar. 2, 1954 

